Dividends (Details) (USD $)	1 Months Ended	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Dividends [Abstract]
Percent increase in quarterly cash dividend declared but not paid in current quarter over dividend paid in current quarter	7.00%
Cash dividends declared per share of common stock (in dollars per share)		$ 0.28	$ 0.17	$ 0.77	$ 0.51
New quarterly dividend payments per share of common stock	$ 0.30	$ 0.30		$ 0.30